In the past, vehicle headlights were usually fixed. This means that they could only shine in the direction predetermined by the orientation of the vehicle. Such a rigid light distribution does not yield ideal results when the road is winding or when the vehicle is turning, since relevant areas of the route are not well illuminated. Therefore, adaptive headlights were initially introduced that dynamically adjust the lighting direction of the vehicle headlights, for example based on the steering angle or map data that provide the course of the route traveled. These headlights allow improved adjustment of the light distribution of the vehicle headlights to actual requirements, especially when taking bends and turning corners.
For normal operation, such as in developed areas or outside of developed areas with oncoming or preceding traffic, vehicle headlights are usually operated at low beam. Typically, the functionality of high beam lighting is provided, which has a considerably longer range and better illuminates the route to be traveled. In this way, a driver can better identify the course of the road and any obstacles. However, since high beam headlights would dazzle oncoming or preceding traffic, they can only be used if there are no other road users within the range of the high beam headlights.
High beam headlights were typically manually controlled in the past; the driver could switch them to high or low beam using a lever or switch. More recent systems can automatically control high beam headlights based on camera data. For example, oncoming or preceding road users are detected by their headlights or tail lights, and high beam headlights are switched on or off depending on whether such road users are present or not. This relieves the driver, avoids dazzling other road users due to late switching to low beam, and allows fast switching to high beam in situations in which there are no other road users in the illumination range of the high beam headlights. Such systems for automatic switching to high or low beam are also called high beam assist.
Another improvement of the concept of high beam assist are the new systems in which the light distribution of the headlights is adapted dynamically. Oncoming or preceding vehicles can be detected by their headlights or tail lights, but the headlights can also be switched to high beam if there are such vehicles in the illumination range of the high beam headlights. In this case, the headlight range can be adjusted automatically so that the headlights only illuminate an area in which other road users are not dazzled. It is also possible to take a dynamically adjustable tunnel out of a widely illuminating high beam light cone, which is selected such that an oncoming or preceding vehicle is exactly located in this tunnel. This prevents the system from dazzling the driver of that vehicle, while still providing the best possible illumination range of the vehicle headlights.
It is a disadvantage of existing systems for the light distribution of vehicle headlights that these systems need additional components such as a camera or a digital road map. The need for such comparatively expensive components can hinder the introduction of high beam assist systems, which provide a considerable increase in safety, especially in vehicles of the lower price segment.